procgroup

Overview ¶

Package procgroup gives the spawn sites that wrap a command with the host sandbox (internal/sandbox) a small, OS-specific way to stop the whole process tree they start, not just the direct child pid.

A sandboxed long-running child (an ACP terminal, an MCP stdio server, a mesnada sub-agent CLI) may actually be a launcher in front of the real program: bubblewrap on Linux, or a shell script a template/ACP agent config points at. Signalling only the direct pid can leave the real work running, or leave grandchildren behind once the launcher exits. Putting the child in its own process group (Ensure, called before Start) and signalling that group (Kill) reaches the launcher and everything it spawned in one call, the same pattern internal/llm/tools/shell already uses for the persistent shell.

Ensure is safe to call unconditionally, whether or not the command ends up wrapped by the sandbox: grouping is a general cleanup improvement, not a sandbox-only concern (a plain shell script can spawn children too).